/**
 * Created by sony on 2017/4/26.
 */
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.interfaces.*;
import java.security.interfaces.*;
import java.math.*;
import java.io.*;
public class week1005 {
        public static void main(String args[]) throws Exception{
            String s="Hello World!";
            // 获取公钥及参数e,n
            FileInputStream f=new FileInputStream("Skey_RSA_pub.dat");
            ObjectInputStream b=new ObjectInputStream(f);
            RSAPublicKey  pbk=(RSAPublicKey)b.readObject( );
            BigInteger e=pbk.getPublicExponent();
            BigInteger n=pbk.getModulus();
            System.out.println("e= "+e);
            System.out.println("n= "+n);
            // 明文 m
            byte ptext[]=s.getBytes("UTF8");
            BigInteger m=new BigInteger(ptext);
            // 计算密文c,打印
            BigInteger c=m.modPow(e,n);
            System.out.println("c= "+c);
            // 保存密文
            String cs=c.toString( );
            BufferedWriter out=
                    new BufferedWriter(new OutputStreamWriter(
                            new FileOutputStream("Enc_RSA.dat")));
            out.write(cs,0,cs.length( ));
            out.close( );

        }
    }
